We're No. 1!

Arizona is the fastest-growing state in the nation. That may not be such cause for celebration.

Homebuilding on the southwest side has exploded since county officials have restricted development in the northwest.

Arlan Colton's office is something of a disaster area. Colton, who heads up Pima County's planning efforts, has thick stacks of reports, memos and maps on every surface in the room--the desk, the table, the bookshelves, the filing cabinets, even much of the floor.

That's not to say Colton doesn't know where everything is--he takes just a couple of minutes to dig up a letter he wants to share--but it's clear that the keeping up with Pima County's development is no easy task.

"Historically, every year, I'd go through all this stuff and sort it and clean up," he says. "But things are going so fast and furious that I don't have time to do that."

Fast and furious may be an understatement. Pima County's population, set at 843,746 in the 2000 census, recently topped 1 million by official estimates.

Population growth is hardly a trend isolated to Pima County. Between 2000 and 2005, the Census Bureau estimated that Arizona's population grew nearly 16 percent, from 5,130,632 to 5,939,292. More recently, the federal agency announced late last year that Arizona, with a growth rate of 3.6 percent, had overtaken Nevada as the nation's fastest-growing state between July 1, 2005 and July 1, 2006, adding more than 213,000 people during that period.

The projected population is even more staggering. In 2005, the Census Bureau estimated that by 2030, Arizona would add another 5.6 million, which would nearly double the state's population.

Those estimates have both local and state officials talking about growth. Tucson Mayor Bob Walkup announced just last week that developer Westcor is working with the State Land Department to plan 8,000 acres of state trust land on the southeast side, including a new shopping center. GOP lawmakers are talking about accelerating highway construction. And Gov. Janet Napolitano has declared growth management to be at the top of her agenda as she starts her second term.

Carolyn Campbell, executive director of the Coalition for Sonoran Desert Protection, welcomes the conversation, although she says it's long overdue.

"There's a recognition that there are huge costs to this kind of growth that 10 years ago, 20 years ago, people weren't realizing," Campbell says.

One glance at the hundreds of reports related to the Sonoran Desert Conservation Plan will tell you that over the last eight years, Pima County officials have undertaken one of the nation's most complex planning efforts.

The end result: The county now has an overall blueprint that lays out how sensitive lands should be preserved while development is pushed to more appropriate land--even if there are still disputes, such as the recent complaints from environmentalists such as Campbell that the county isn't doing enough to protect land on the northwest side.

County Administrator Chuck Huckelberry says the Sonoran Desert Conservation Plan puts Pima County about a decade ahead of the rest of the state. But even though the county has a plan to manage growth, it still has a lot to of work ahead in figuring out how to pay for it.

Huckelberry says there are three basic stages to effective planning. The first, identifying where to build and where to preserve, has already been accomplished through the Sonoran Desert Conservation Plan.

The second stage is figuring out what kind of development you want in the areas where you want to build. Huckelberry says the key to better development involves higher density. He points out that Tucson's density peaked in the 1950s and has been declining ever since.

"Everybody wants to live on an acre lot with a large house," Huckelberry says. That drives up the cost of delivering services and providing roads and other infrastructure while chewing up the desert.

Huckelberry says current zoning regulations encourage that kind of sprawl. He suggests a change to zoning regs to encourage more mixed-use development that blends retail with residential. "Actually getting some real-world mixed use on the ground is our next challenge," he says. "That's where you begin to take some of the pressure off our No. 1 stressed infrastructure, called transportation."

The final stage of planning: figuring out how to pay for all the additional demands created by growth--streets, sewer systems, parks, libraries, schools, police, courts and other government services.

The county has been making some steps in that direction; transportation impact fees, enacted in 1996, have raised nearly $75 million, according to a recent report. But with property taxes always on the rise, it's obvious that current residents are footing a growth bill.

And some of those costs still aren't clear. In many cases, Huckelberry is still playing catch-up. For example, he's asked Colton's planning department to determine the infrastructure needs in the southwest corridor along Valencia Road and Ajo Way, where growth has exploded in recent years as a result of development restrictions on the northwest side. Some needs are obvious: wider streets and flood-control work to prevent the roads from sinking underwater during heavy rains.

"Growth isn't going to go away," Huckelberry says. "We can't stick our heads in the sand of the Rillito River and assume that it's not happening. It is. Good, solid land-use planning includes a recognition that growth is occurring, knowing what to conserve and knowing what to develop, and then figuring out how to pay for it so everyone isn't overburdened by the congestion that comes from growth--which can be as simple as sitting on the Interstate and not being able to travel, or not getting a library book because they're all checked out."

Albert Elias, who heads up planning for the city of Tucson, agrees with Huckelberry about the need for more mixed-use development. He says the city is now working on new zoning categories that will allow residential and retail development both within the existing city and in future growth areas.

Elias says one major challenge for Tucson is balancing the needs of the existing city with the demands of development on the southeast side, where the city has annexed vast acres of mostly vacant land.

Much of that property has been identified as the Southlands planning area, which covers 1,083 square miles, including a vacant 868 square miles. Roughly half of the vacant land is state trust land that must ultimately be auctioned for development, with the money going to support education.

The Southlands area, which had about 14,200 residents in 1980, is now home to about 55,000 people. While that's a significant jump, there's lots more to come: The Pima Association of Governments estimates that by 2015, more than 118,000 people will live there; by 2030, it could be home to more than a quarter-million--while the city of Tucson itself will have an estimated 910,000 residents and Pima County will be home to more than 1.5 million.

The city's Planning Department is trying to guide that development. It's already assembled the Houghton Area Master Plan (HAMP), which is a 4-mile-wide corridor along Houghton Road that covers 16.9 square miles, stretching from Irvington Road on the north to the city limits on the south. About three-fourths of the land belongs to the State Land Department, which is the city's planning partner.

Elias says the HAMP is a first step toward planning the entire area, but the city wants to see how well it works before embarking on more planning efforts.

The HAMP calls for development based on a "desert village" model, which the plan defines as "a mix of uses within a compact development pattern, which integrates places for people to live, work, shop, play within a cohesive system of Neighborhoods and Village and Town Centers."

Elias says planning at a larger scale makes that kind of mixed-use development possible, as well as allowing for desert conservation in the form of parks. Planners can also lay out road and trail systems that accommodate cars, bikes, pedestrians and mass transit.

"We want to get away from the just-one-subdivision-at-a-time sort of thing and do a better mixing of land uses and more variety of housing types," Elias says. "And you can best do that at a larger scale."

With very little infrastructure in place, however, the cost of building that new Tucson without repeating the mistakes of the past--subdivisions linked by two-lane roads on the northwest side, for example--will be enormous. While the city has impact fees for transportation and parks now in place, it remains to be seen how much money they will provide for an area on the scale of the Southlands.

One thing they definitely will not pay for is a wider Interstate 10--which will also be burdened by development further south, in southeastern Pima and Cochise counties.

Elias says the city can do some things, such as setting aside right-of-way for the eventual widening of I-10. But he adds that the state needs to step up its planning efforts in concert with the local governments.

"Before we used to think of regional planning at the level of our metropolitan area," Elias says. "One of things we're learning is that we've got to think about things like the Interstate on a different scale."

When it comes to the really large scale, you turn to people like Virginia Tech professor Robert Lang, who predicts that Arizona will be home to more than 10 million people in "megapolitan area" he calls the Valley of the Sun.

Lang foresees the U.S. as having 10 of these megapolitan areas, which he defines as areas that combine at least two major metropolitan areas in a roughly similar physical environment that will have at least 10 million residents by 2040. The Valley of the Sun will be one long corridor stretching from Sierra Vista and Nogales all the way north of Phoenix.

Lang's vision for Arizona fits pretty well with most of the growth predictions. Already, developers are eyeing opportunities in neighboring counties--particularly Pinal County to the north and Cochise County to the south.

Unfortunately, Pima County residents can't do much to control what happens in either direction, even though the growth will impact our lives.

Pinal County, between Pima and Maricopa, will experience rapid growth as both the Tucson and Phoenix metro areas expand. Some planners expect that it will have a larger population than Pima County by 2030, although Huckelberry remains skeptical of the prediction.

In any event, the drive to Phoenix is bound to get more congested. The Arizona Legislature set aside $300 million last year to accelerate highway construction.

Of that, $109 million has been targeted to widen Interstate 10 to three lanes in each direction all the way to Picacho Peak.

In her State of the State speech last month, Napolitano announced she had directed the Arizona Department of Transportation to do a survey of transportation options that included wider highways and even a long-discussed rail service between Tucson and Phoenix.

Campbell likes the idea of more mass transit between the metro areas, although she says it could have a significant downside.

"I'm not absolutely sure that's not going to get a lot more people who live in Phoenix to move to Tucson," Campbell laughs. "But at least then we'd have the rail option, which people have been talking about for a long time. And if that happened, we'd have to have some kind of transit within the communities that we're connecting, so we don't have to have massive parking lots at each end of the rail system."

So far, there's no funding set aside for widening I-10 east of Tucson, even though there's tremendous growth planned for Cochise County. Huckelberry warns that without more lanes, Interstate 10 will come to resemble a "parking lot."

"It's a big problem," Huckelberry says. "Someday, we're going to wake up and wonder why it takes us two hours to get to Benson."

Still, Huckelberry has confidence in the planning staffs in the neighboring counties.

"The smaller counties have got good planning staffs," Huckelberry says. "The boards recognize the challenge that growth presents, so I think there is some real opportunity for a lot of cooperative planning among the counties. It's the first time I've seen a lot of real dialogue that's direct and open."

But Campbell worries that even with planning efforts, development won't pay for itself.

"When we talk about the financial costs of growth--regardless of the air quality, the water quality, the congestion of the streets and all that--we always seem to be a few steps behind in having money to address the problems," she says. "We're always dealing with it after the fact."

Even more important: She wonders where new residents will get their drinking water.

"There are a lot of issues about the limited supply of water and both environmental and human needs that haven't been addressed," Campbell says.

"Growth is not all it's cracked up to be," says Campbell. "People are beginning to realize that. Even just a few years ago, political leaders were afraid to talk about controlled growth. At least they're talking about that now."